AB0913 EFFICACY AND SAFETY OF SWITCHING FROM FILGOTINIB TO TOFACITINIB IN PATIENTS WITH PSORIATIC ARTHRITIS AFTER 6 MONTHS OF FOLLOW-UP
Authors: I. Gonzalez-Mazon, J. Loricera, L. Sanchez-Bilbao, A. Corrales, M. A. González-Gay, R. Blanco
Journal: Annals of the Rheumatic Diseases (2022)

Background Phase 2 studies have shown that Filgotinib (FIL), a JAK-inhibitor (JAKi), significantly improves signs and symptoms of psoriatic arthritis (PsA) in patients with active disease. PENGUIN 1 and 2 were two phase III trials of FIL in PsA that were stopped. We considered Tofacitinib (TOFA) the best alternative drug for these patients because TOFA is the only JAKi approved so far in Spain for PsA. However, data in clinical practice about switching from FIL to TOFA have not been reported. Objectives To assess the efficacy and safety of switching FIL to TOFA in patients with PsA. Methods Prospective Single-University-hospital study of PsA patients diagnosed according to CASPAR criteria, and previously treated with FIL 100 mg and 200 mg/day in two clinical trials (PENGUIN 1 and 2). Based on a shared decision between the patient and the physician, once the trial was finished, patients receiving FIL were switched to TOFA (5 mg/12h) with a 7 days wash-up period. PsA activity, analytical and ultrasound outcomes were assessed at baseline and after 1, 3 and 6 months of treatment with TOFA. A power doppler ultrasound score (PDUS) was obtained using a scoring system which assessed bilateral midline wrists, metacarpophalangeal joints 1-5, proximal and distal interphalangeal joints 2–5 in hands and feet, bilateral knees, ankles and metatarsophalangeal joints 2-5 (apart from any other painful joint). Each image was scored semi-quantitatively on a scale of 0-3. We used MASEI index for the enthesis US evaluation (that includes entheses at 6 sites: proximal plantar fascia, distal Achilles tendon, distal and proximal patellar tendon insertion, distal quadriceps tendon and distal brachial triceps tendon). We also evaluated in these enthesis the presence/absence (0/1) of PD signal as it is the main activity signal. Results We included 11 patients (6 women/5 men) with a mean age of 52.5±6.5 years who had received FIL during a mean time of 16.0±9.3 weeks. JAKi was used in monotherapy or combined with sulfasalazine (n=2), methotrexate (n=1) and apremilast (n=1). Disease activity, US scores and laboratory values during the follow-up are shown in Table 1. No significant changes were observed in any case. Table 1. Psoriatic Arthritis activity, ultrasound and analytical outcomes at baseline, month 1, 3 and 6. Baseline Month 1 Month 3 Month 6 p Musculoskeletal activity scores, median [IQR] TJC – no. 2 [0-3] 3 [1.5-16] 1 [0-12] 2 [0-5] 0.22 SJC – no. 0 [0-0] 0 [0-5] 0 [0-6] 0 [0-2] 0.09 Ultrasound exam, median [IQR] PDUS score (0-90) 2 [1-9] 3 [1-6] 2 [0-4] 2 [2-9] 0.99 Enthesitis according to PDUS (n) 1 [0-2] 1 [0-2] 0 [0-2] 1 [0-1] 0.85 MASEI index 16.5 ±10.5 19.6 ± 14.5 15.5 ± 4.8 17.5 ± 11.8 0.82 Laboratory values Hemoglobin (g/dl) - mean±SD 13.96 ± 1.40 13.54 ± 1.38 13.79 ±1.60 14.40 ± 1.75 0.64 Leucocytes (x103/µL) - mean±SD 7.10 ± 3.40 7.27 ± 2.96 7.14 ± 2.89 8.20 ± 2.87 0.89 Lymphocytes (x103/µL) - mean±SD 2.03 ± 1.01 1.94 ± 0.95 2.16 ± 0.86 1.96 ± 0.45 0.94 Neutrophils (x103/µL) - mean±SD 4.24 ± 2.92 4.54 ± 1.97 4.18 ± 1.84 5.30 ± 2.37 0.85 Platelet count (x103/µL) - mean±SD 266.44 ± 57.35 250.67 ± 53.29 264.90 ± 56.78 287.20 ± 25.58 0.69 CRP (mg/dl) - median [IQR] 0.00 [0.00-1.70] 0.00 [0.00-0.00] 0.00 [0.00-0.00] 0.00 [0.00-0.00] 0.12 ESR (mm/h) - median [IQR] 15 [6-19] 9 [5-15] 12 [4-15] 13 [5-45] 0.12 CRP: C-reactive protein; ESR: Erythrocyte sedimentation rate; MASEI: Madrid Sonographic Enthesis Index; TJC: Tender joint count; PDUS: Power doppler ultrasound; SJC: Swollen joint count. No adverse events were reported during the 6 month of follow-up except for 1 patient with lymphopenia (500/µL). TOFA was discontinued after 1 month in 1 patient because of lypmphopenia and inefficacy and after 3 months in 4 patients for worsening of the joint pain. It was remarkable that in some of the patients who reported a worsening of painful joints we did not observed a higher inflammatory activity in the SJC or US exam, and this incongruity could be due to the role that JAK/STAT inhibition plays in pain signaling pathways. Conclusion Switching from FIL to TOFA appears to be an effective and safe therapeutic option. Disclosure of Interests None declared